The present invention relates to an underwater bearing protection device for preventing rapid abrasion of the bearings in equipment for removing sand in a cleaning bed of a filtration plant or for using in the settling basins, in which sand, sewage, etc. are deposited, in drainage disposal plants, sewage disposal plants or paper manufacturing.
Conventional underwater bearings of sewage scrapers, disposing sand scraping lifters, agitators, pump, etc. are remarkably worn by the invasion of sand and mire.
For removing this defect, the applicant of this application proposed an underwater bearing protection device in which a bushing is rotatably mounted on a sleeve attached to a fixed shaft, a hub is fixed on the bushing, both sides of the hub are covered by outer edges of collars, the inner edges of which are respectively fixed on the bushing, O rings are mounted between the both edges of hub and the outer edges of the collars, the flange of a chain wheel is fixed on the hub and thus, the flange, the hub and the bushing are rotated (see Japanese Patent Publication No. 54653/82).
In the underwater bearing protection device, for preventing the invasion of sand and mire from the portions of the O rings between the outer edges of the collars and the both sides of hub due to the rotation of the flange, clean water is passed into the center water supplying passage which is provided with the center of the fixed shaft through the water pipe which is attached on the fixed shaft. This is supplied to a ring-like hole which is provided with the bushing and hub from the the center water supplying passage through the sleeve and flows from inclined water supplying passages through the ring-like hole to the outside edges.
However, in order that the inclined water supplying passages are opened at constant interval in the peripheries of that both sides of the hub near the gaps between the both edges of the hub and the the outside edges of the collars, the clean water may be equally caused to flow to the outer side edges of the collars. Therefore, when many foreign materials such as floating sand and so on are deposited in a cleaning bed, there is the problem that this sealing effect is not sufficient.